1. Field of the Invention
The instant disclosure relates to a semiconductor device; more particularly, to a trench power device and a manufacturing method thereof
2. Description of Related Art
The power device is used to manage power, and the type of power device includes metal-oxide-semiconductor thin film transistor (MOSFET), bipolar junction transistor (BJT), and insulated gate bipolar transistor (IGBT). The MOSFET is widely applied because the MOSFET is capable of saving energy and faster switching rate.
The conventional type of MOSFET includes a thick bottom oxide structure and split gate structure, and they have some problems, which need to improve. For example, Ciss/Crss of the thick bottom oxide structure is about 13 and can be further improved. The split gate structure has difficult manufacturing process because the oxide layer of semiconductor layer is hard to be controlled for separating the gate from the source.
To achieve the abovementioned improvement, the inventors strive via industrial experience and academic research to present the instant disclosure, which can provide additional improvement as mentioned above.